/*
* Copyright 2012 The Netty Project
*
* The Netty Project licenses this file to you under the Apache License,
* version 2.0 (the "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*/
package io.netty.channel;
import io.netty.channel.Channel.Unsafe;
import io.netty.util.ReferenceCountUtil;
import io.netty.util.concurrent.EventExecutor;
import io.netty.util.concurrent.EventExecutorGroup;
import io.netty.util.internal.OneTimeTask;
import io.netty.util.internal.PlatformDependent;
import io.netty.util.internal.StringUtil;
import io.netty.util.internal.logging.InternalLogger;
import io.netty.util.internal.logging.InternalLoggerFactory;
import java.net.SocketAddress;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.IdentityHashMap;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.WeakHashMap;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
/**
* The default {@link ChannelPipeline} implementation. It is usually created
* by a {@link Channel} implementation when the {@link Channel} is created.
*/
final class DefaultChannelPipeline implements ChannelPipeline {
static final InternalLogger logger = InternalLoggerFactory.getInstance(DefaultChannelPipeline.class);
@SuppressWarnings("unchecked")
private static final WeakHashMap<Class<?>, String>[] nameCaches =
new WeakHashMap[Runtime.getRuntime().availableProcessors()];
static {
for (int i = 0; i < nameCaches.length; i ++) {
nameCaches[i] = new WeakHashMap<Class<?>, String>();
}
}
final AbstractChannel channel;
final AbstractChannelHandlerContext head;
final AbstractChannelHandlerContext tail;
private final Map<String, AbstractChannelHandlerContext> name2ctx =
new HashMap<String, AbstractChannelHandlerContext>(4);
final Map<EventExecutorGroup, EventExecutor> childExecutors =
new IdentityHashMap<EventExecutorGroup, EventExecutor>();
DefaultChannelPipeline(AbstractChannel channel) {
if (channel == null) {
throw new NullPointerException("channel");
}
this.channel = channel;
tail = new TailContext(this);
head = new HeadContext(this);
head.next = tail;
tail.prev = head;
}
@Override
public Channel channel() {
return channel;
}
@Override
public ChannelPipeline addFirst(String name, ChannelHandler handler) {
return addFirst(null, name, handler);
}
@Override
public ChannelPipeline addFirst(EventExecutorGroup group, final String name, ChannelHandler handler) {
synchronized (this) {
checkDuplicateName(name);
AbstractChannelHandlerContext newCtx = new DefaultChannelHandlerContext(this, group, name, handler);
addFirst0(name, newCtx);
}
return this;
}
private void addFirst0(String name, AbstractChannelHandlerContext newCtx) {
checkMultiplicity(newCtx);
AbstractChannelHandlerContext nextCtx = head.next;
newCtx.prev = head;
newCtx.next = nextCtx;
head.next = newCtx;
nextCtx.prev = newCtx;
name2ctx.put(name, newCtx);
callHandlerAdded(newCtx);
}
@Override
public ChannelPipeline addLast(String name, ChannelHandler handler) {
return addLast(null, name, handler);
}
@Override
public ChannelPipeline addLast(EventExecutorGroup group, final String name, ChannelHandler handler) {
synchronized (this) {
checkDuplicateName(name);
AbstractChannelHandlerContext newCtx = new DefaultChannelHandlerContext(this, group, name, handler);
addLast0(name, newCtx);
}
return this;
}
private void addLast0(final String name, AbstractChannelHandlerContext newCtx) {
checkMultiplicity(newCtx);
AbstractChannelHandlerContext prev = tail.prev;
newCtx.prev = prev;
newCtx.next = tail;
prev.next = newCtx;
tail.prev = newCtx;
name2ctx.put(name, newCtx);
callHandlerAdded(newCtx);
}
@Override
public ChannelPipeline addBefore(String baseName, String name, ChannelHandler handler) {
return addBefore(null, baseName, name, handler);
}
@Override
public ChannelPipeline addBefore(
EventExecutorGroup group, String baseName, final String name, ChannelHandler handler) {
synchronized (this) {
AbstractChannelHandlerContext ctx = getContextOrDie(baseName);
checkDuplicateName(name);
AbstractChannelHandlerContext newCtx = new DefaultChannelHandlerContext(this, group, name, handler);
addBefore0(name, ctx, newCtx);
}
return this;
}
private void addBefore0(
final String name, AbstractChannelHandlerContext ctx, AbstractChannelHandlerContext newCtx) {
checkMultiplicity(newCtx);
newCtx.prev = ctx.prev;
newCtx.next = ctx;
ctx.prev.next = newCtx;
ctx.prev = newCtx;
name2ctx.put(name, newCtx);
callHandlerAdded(newCtx);
}
@Override
public ChannelPipeline addAfter(String baseName, String name, ChannelHandler handler) {
return addAfter(null, baseName, name, handler);
}
@Override
public ChannelPipeline addAfter(
EventExecutorGroup group, String baseName, final String name, ChannelHandler handler) {
synchronized (this) {
AbstractChannelHandlerContext ctx = getContextOrDie(baseName);
checkDuplicateName(name);
AbstractChannelHandlerContext newCtx = new DefaultChannelHandlerContext(this, group, name, handler);
addAfter0(name, ctx, newCtx);
}
return this;
}
private void addAfter0(final String name, AbstractChannelHandlerContext ctx, AbstractChannelHandlerContext newCtx) {
checkDuplicateName(name);
checkMultiplicity(newCtx);
newCtx.prev = ctx;
newCtx.next = ctx.next;
ctx.next.prev = newCtx;
ctx.next = newCtx;
name2ctx.put(name, newCtx);
callHandlerAdded(newCtx);
}
@Override
public ChannelPipeline addFirst(ChannelHandler... handlers) {
return addFirst(null, handlers);
}
@Override
public ChannelPipeline addFirst(EventExecutorGroup executor, ChannelHandler... handlers) {
if (handlers == null) {
throw new NullPointerException("handlers");
}
if (handlers.length == 0 || handlers[0] == null) {
return this;
}
int size;
for (size = 1; size < handlers.length; size ++) {
if (handlers[size] == null) {
break;
}
}
for (int i = size - 1; i >= 0; i --) {
ChannelHandler h = handlers[i];
addFirst(executor, generateName(h), h);
}
return this;
}
@Override
public ChannelPipeline addLast(ChannelHandler... handlers) {
return addLast(null, handlers);
}
@Override
public ChannelPipeline addLast(EventExecutorGroup executor, ChannelHandler... handlers) {
if (handlers == null) {
throw new NullPointerException("handlers");
}
for (ChannelHandler h: handlers) {
if (h == null) {
break;
}
addLast(executor, generateName(h), h);
}
return this;
}
private String generateName(ChannelHandler handler) {
WeakHashMap<Class<?>, String> cache = nameCaches[(int) (Thread.currentThread().getId() % nameCaches.length)];
Class<?> handlerType = handler.getClass();
String name;
synchronized (cache) {
name = cache.get(handlerType);
if (name == null) {
name = generateName0(handlerType);
cache.put(handlerType, name);
}
}
synchronized (this) {
// It's not very likely for a user to put more than one handler of the same type, but make sure to avoid
// any name conflicts. Note that we don't cache the names generated here.
if (name2ctx.containsKey(name)) {
String baseName = name.substring(0, name.length() - 1); // Strip the trailing '0'.
for (int i = 1;; i ++) {
String newName = baseName + i;
if (!name2ctx.containsKey(newName)) {
name = newName;
break;
}
}
}
}
return name;
}
private static String generateName0(Class<?> handlerType) {
return StringUtil.simpleClassName(handlerType) + "#0";
}
@Override
public ChannelPipeline remove(ChannelHandler handler) {
remove(getContextOrDie(handler));
return this;
}
@Override
public ChannelHandler remove(String name) {
return remove(getContextOrDie(name)).handler();
}
@SuppressWarnings("unchecked")
@Override
public <T extends ChannelHandler> T remove(Class<T> handlerType) {
return (T) remove(getContextOrDie(handlerType)).handler();
}
private AbstractChannelHandlerContext remove(final AbstractChannelHandlerContext ctx) {
assert ctx != head && ctx != tail;
AbstractChannelHandlerContext context;
Future<?> future;
synchronized (this) {
if (!ctx.channel().isRegistered() || ctx.executor().inEventLoop()) {
remove0(ctx);
return ctx;
} else {
future = ctx.executor().submit(new Runnable() {
@Override
public void run() {
synchronized (DefaultChannelPipeline.this) {
remove0(ctx);
}
}
});
context = ctx;
}
}
// Run the following 'waiting' code outside of the above synchronized block
// in order to avoid deadlock
waitForFuture(future);
return context;
}
void remove0(AbstractChannelHandlerContext ctx) {
AbstractChannelHandlerContext prev = ctx.prev;
AbstractChannelHandlerContext next = ctx.next;
prev.next = next;
next.prev = prev;
name2ctx.remove(ctx.name());
callHandlerRemoved(ctx);
}
@Override
public ChannelHandler removeFirst() {
if (head.next == tail) {
throw new NoSuchElementException();
}
return remove(head.next).handler();
}
@Override
public ChannelHandler removeLast() {
if (head.next == tail) {
throw new NoSuchElementException();
}
return remove(tail.prev).handler();
}
@Override
public ChannelPipeline replace(ChannelHandler oldHandler, String newName, ChannelHandler newHandler) {
replace(getContextOrDie(oldHandler), newName, newHandler);
return this;
}
@Override
public ChannelHandler replace(String oldName, String newName, ChannelHandler newHandler) {
return replace(getContextOrDie(oldName), newName, newHandler);
}
@Override
@SuppressWarnings("unchecked")
public <T extends ChannelHandler> T replace(
Class<T> oldHandlerType, String newName, ChannelHandler newHandler) {
return (T) replace(getContextOrDie(oldHandlerType), newName, newHandler);
}
private ChannelHandler replace(
final AbstractChannelHandlerContext ctx, final String newName,
ChannelHandler newHandler) {
assert ctx != head && ctx != tail;
Future<?> future;
synchronized (this) {
boolean sameName = ctx.name().equals(newName);
if (!sameName) {
checkDuplicateName(newName);
}
final AbstractChannelHandlerContext newCtx =
new DefaultChannelHandlerContext(this, ctx.executor, newName, newHandler);
if (!newCtx.channel().isRegistered() || newCtx.executor().inEventLoop()) {
replace0(ctx, newName, newCtx);
return ctx.handler();
} else {
future = newCtx.executor().submit(new Runnable() {
@Override
public void run() {
synchronized (DefaultChannelPipeline.this) {
replace0(ctx, newName, newCtx);
}
}
});
}
}
// Run the following 'waiting' code outside of the above synchronized block
// in order to avoid deadlock
waitForFuture(future);
return ctx.handler();
}
private void replace0(AbstractChannelHandlerContext oldCtx, String newName,
AbstractChannelHandlerContext newCtx) {
checkMultiplicity(newCtx);
AbstractChannelHandlerContext prev = oldCtx.prev;
AbstractChannelHandlerContext next = oldCtx.next;
newCtx.prev = prev;
newCtx.next = next;
// Finish the replacement of oldCtx with newCtx in the linked list.
// Note that this doesn't mean events will be sent to the new handler immediately
// because we are currently at the event handler thread and no more than one handler methods can be invoked
// at the same time (we ensured that in replace().)
prev.next = newCtx;
next.prev = newCtx;
if (!oldCtx.name().equals(newName)) {
name2ctx.remove(oldCtx.name());
}
name2ctx.put(newName, newCtx);
// update the reference to the replacement so forward of buffered content will work correctly
oldCtx.prev = newCtx;
oldCtx.next = newCtx;
// Invoke newHandler.handlerAdded() first (i.e. before oldHandler.handlerRemoved() is invoked)
// because callHandlerRemoved() will trigger inboundBufferUpdated() or flush() on newHandler and those
// event handlers must be called after handlerAdded().
callHandlerAdded(newCtx);
callHandlerRemoved(oldCtx);
}
private static void checkMultiplicity(ChannelHandlerContext ctx) {
ChannelHandler handler = ctx.handler();
if (handler instanceof ChannelHandlerAdapter) {
ChannelHandlerAdapter h = (ChannelHandlerAdapter) handler;
if (!h.isSharable() && h.added) {
throw new ChannelPipelineException(
h.getClass().getName() +
" is not a @Sharable handler, so can't be added or removed multiple times.");
}
h.added = true;
}
}
private void callHandlerAdded(final AbstractChannelHandlerContext ctx) {
if (ctx.channel().isRegistered() && !ctx.executor().inEventLoop()) {
ctx.executor().execute(new Runnable() {
@Override
public void run() {
callHandlerAdded0(ctx);
}
});
return;
}
callHandlerAdded0(ctx);
}
private void callHandlerAdded0(final AbstractChannelHandlerContext ctx) {
try {
ctx.invokedThisChannelRead = false;
ctx.handler().handlerAdded(ctx);
} catch (Throwable t) {
boolean removed = false;
try {
remove(ctx);
removed = true;
} catch (Throwable t2) {
if (logger.isWarnEnabled()) {
logger.warn("Failed to remove a handler: " + ctx.name(), t2);
}
}
if (removed) {
fireExceptionCaught(new ChannelPipelineException(
ctx.handler().getClass().getName() +
".handlerAdded() has thrown an exception; removed.", t));
} else {
fireExceptionCaught(new ChannelPipelineException(
ctx.handler().getClass().getName() +
".handlerAdded() has thrown an exception; also failed to remove.", t));
}
}
}
private void callHandlerRemoved(final AbstractChannelHandlerContext ctx) {
if (ctx.channel().isRegistered() && !ctx.executor().inEventLoop()) {
ctx.executor().execute(new Runnable() {
@Override
public void run() {
callHandlerRemoved0(ctx);
}
});
return;
}
callHandlerRemoved0(ctx);
}
private void callHandlerRemoved0(final AbstractChannelHandlerContext ctx) {
// Notify the complete removal.
try {
ctx.handler().handlerRemoved(ctx);
ctx.setRemoved();
} catch (Throwable t) {
fireExceptionCaught(new ChannelPipelineException(
ctx.handler().getClass().getName() + ".handlerRemoved() has thrown an exception.", t));
}
}
/**
* Waits for a future to finish. If the task is interrupted, then the current thread will be interrupted.
* It is expected that the task performs any appropriate locking.
* <p>
* If the internal call throws a {@link Throwable}, but it is not an instance of {@link Error} or
* {@link RuntimeException}, then it is wrapped inside a {@link ChannelPipelineException} and that is
* thrown instead.</p>
*
* @param future wait for this future
* @see Future#get()
* @throws Error if the task threw this.
* @throws RuntimeException if the task threw this.
* @throws ChannelPipelineException with a {@link Throwable} as a cause, if the task threw another type of
* {@link Throwable}.
*/
private static void waitForFuture(Future<?> future) {
try {
future.get();
} catch (ExecutionException ex) {
// In the arbitrary case, we can throw Error, RuntimeException, and Exception
PlatformDependent.throwException(ex.getCause());
} catch (InterruptedException ex) {
// Interrupt the calling thread (note that this method is not called from the event loop)
Thread.currentThread().interrupt();
}
}
@Override
public ChannelHandler first() {
ChannelHandlerContext first = firstContext();
if (first == null) {
return null;
}
return first.handler();
}
@Override
public ChannelHandlerContext firstContext() {
AbstractChannelHandlerContext first = head.next;
if (first == tail) {
return null;
}
return head.next;
}
@Override
public ChannelHandler last() {
AbstractChannelHandlerContext last = tail.prev;
if (last == head) {
return null;
}
return last.handler();
}
@Override
public ChannelHandlerContext lastContext() {
AbstractChannelHandlerContext last = tail.prev;
if (last == head) {
return null;
}
return last;
}
@Override
public ChannelHandler get(String name) {
ChannelHandlerContext ctx = context(name);
if (ctx == null) {
return null;
} else {
return ctx.handler();
}
}
@SuppressWarnings("unchecked")
@Override
public <T extends ChannelHandler> T get(Class<T> handlerType) {
ChannelHandlerContext ctx = context(handlerType);
if (ctx == null) {
return null;
} else {
return (T) ctx.handler();
}
}
@Override
public ChannelHandlerContext context(String name) {
if (name == null) {
throw new NullPointerException("name");
}
synchronized (this) {
return name2ctx.get(name);
}
}
@Override
public ChannelHandlerContext context(ChannelHandler handler) {
if (handler == null) {
throw new NullPointerException("handler");
}
AbstractChannelHandlerContext ctx = head.next;
for (;;) {
if (ctx == null) {
return null;
}
if (ctx.handler() == handler) {
return ctx;
}
ctx = ctx.next;
}
}
@Override
public ChannelHandlerContext context(Class<? extends ChannelHandler> handlerType) {
if (handlerType == null) {
throw new NullPointerException("handlerType");
}
AbstractChannelHandlerContext ctx = head.next;
for (;;) {
if (ctx == null) {
return null;
}
if (handlerType.isAssignableFrom(ctx.handler().getClass())) {
return ctx;
}
ctx = ctx.next;
}
}
@Override
public List<String> names() {
List<String> list = new ArrayList<String>();
AbstractChannelHandlerContext ctx = head.next;
for (;;) {
if (ctx == null) {
return list;
}
list.add(ctx.name());
ctx = ctx.next;
}
}
@Override
public Map<String, ChannelHandler> toMap() {
Map<String, ChannelHandler> map = new LinkedHashMap<String, ChannelHandler>();
AbstractChannelHandlerContext ctx = head.next;
for (;;) {
if (ctx == tail) {
return map;
}
map.put(ctx.name(), ctx.handler());
ctx = ctx.next;
}
}
@Override
public Iterator<Map.Entry<String, ChannelHandler>> iterator() {
return toMap().entrySet().iterator();
}
/**
* Returns the {@link String} representation of this pipeline.
*/
@Override
public String toString() {
StringBuilder buf = new StringBuilder()
.append(StringUtil.simpleClassName(this))
.append('{');
AbstractChannelHandlerContext ctx = head.next;
for (;;) {
if (ctx == tail) {
break;
}
buf.append('(')
.append(ctx.name())
.append(" = ")
.append(ctx.handler().getClass().getName())
.append(')');
ctx = ctx.next;
if (ctx == tail) {
break;
}
buf.append(", ");
}
buf.append('}');
return buf.toString();
}
@Override
public ChannelPipeline fireChannelRegistered() {
head.fireChannelRegistered();
return this;
}
@Override
public ChannelPipeline fireChannelUnregistered() {
head.fireChannelUnregistered();
// Remove all handlers sequentially if channel is closed and unregistered.
if (!channel.isOpen()) {
destroy();
}
return this;
}
/**
* Removes all handlers from the pipeline one by one from tail (exclusive) to head (exclusive) to trigger
* handlerRemoved().
*
* Note that we traverse up the pipeline ({@link #destroyUp(AbstractChannelHandlerContext)})
* before traversing down ({@link #destroyDown(Thread, AbstractChannelHandlerContext)}) so that
* the handlers are removed after all events are handled.
*
* See: https://github.com/netty/netty/issues/3156
*/
private void destroy() {
destroyUp(head.next);
}
private void destroyUp(AbstractChannelHandlerContext ctx) {
final Thread currentThread = Thread.currentThread();
final AbstractChannelHandlerContext tail = this.tail;
for (;;) {
if (ctx == tail) {
destroyDown(currentThread, tail.prev);
break;
}
final EventExecutor executor = ctx.executor();
if (!executor.inEventLoop(currentThread)) {
final AbstractChannelHandlerContext finalCtx = ctx;
executor.execute(new OneTimeTask() {
@Override
public void run() {
destroyUp(finalCtx);
}
});
break;
}
ctx = ctx.next;
}
}
private void destroyDown(Thread currentThread, AbstractChannelHandlerContext ctx) {
// We have reached at tail; now traverse backwards.
final AbstractChannelHandlerContext head = this.head;
for (;;) {
if (ctx == head) {
break;
}
final EventExecutor executor = ctx.executor();
if (executor.inEventLoop(currentThread)) {
synchronized (this) {
remove0(ctx);
}
} else {
final AbstractChannelHandlerContext finalCtx = ctx;
executor.execute(new OneTimeTask() {
@Override
public void run() {
destroyDown(Thread.currentThread(), finalCtx);
}
});
break;
}
ctx = ctx.prev;
}
}
@Override
public ChannelPipeline fireChannelActive() {
head.fireChannelActive();
if (channel.config().isAutoRead()) {
channel.read();
}
return this;
}
@Override
public ChannelPipeline fireChannelInactive() {
head.fireChannelInactive();
return this;
}
@Override
public ChannelPipeline fireExceptionCaught(Throwable cause) {
head.fireExceptionCaught(cause);
return this;
}
@Override
public ChannelPipeline fireUserEventTriggered(Object event) {
head.fireUserEventTriggered(event);
return this;
}
@Override
public ChannelPipeline fireChannelRead(Object msg) {
head.fireChannelRead(msg);
return this;
}
@Override
public ChannelPipeline fireChannelReadComplete() {
head.fireChannelReadComplete();
if (channel.config().isAutoRead()) {
read();
}
return this;
}
@Override
public ChannelPipeline fireChannelWritabilityChanged() {
head.fireChannelWritabilityChanged();
return this;
}
@Override
public ChannelFuture bind(SocketAddress localAddress) {
return tail.bind(localAddress);
}
@Override
public ChannelFuture connect(SocketAddress remoteAddress) {
return tail.connect(remoteAddress);
}
@Override
public ChannelFuture connect(SocketAddress remoteAddress, SocketAddress localAddress) {
return tail.connect(remoteAddress, localAddress);
}
@Override
public ChannelFuture disconnect() {
return tail.disconnect();
}
@Override
public ChannelFuture close() {
return tail.close();
}
@Override
public ChannelFuture deregister() {
return tail.deregister();
}
@Override
public ChannelPipeline flush() {
tail.flush();
return this;
}
@Override
public ChannelFuture bind(SocketAddress localAddress, ChannelPromise promise) {
return tail.bind(localAddress, promise);
}
@Override
public ChannelFuture connect(SocketAddress remoteAddress, ChannelPromise promise) {
return tail.connect(remoteAddress, promise);
}
@Override
public ChannelFuture connect(SocketAddress remoteAddress, SocketAddress localAddress, ChannelPromise promise) {
return tail.connect(remoteAddress, localAddress, promise);
}
@Override
public ChannelFuture disconnect(ChannelPromise promise) {
return tail.disconnect(promise);
}
@Override
public ChannelFuture close(ChannelPromise promise) {
return tail.close(promise);
}
@Override
public ChannelFuture deregister(final ChannelPromise promise) {
return tail.deregister(promise);
}
@Override
public ChannelPipeline read() {
tail.read();
return this;
}
@Override
public ChannelFuture write(Object msg) {
return tail.write(msg);
}
@Override
public ChannelFuture write(Object msg, ChannelPromise promise) {
return tail.write(msg, promise);
}
@Override
public ChannelFuture writeAndFlush(Object msg, ChannelPromise promise) {
return tail.writeAndFlush(msg, promise);
}
@Override
public ChannelFuture writeAndFlush(Object msg) {
return tail.writeAndFlush(msg);
}
private void checkDuplicateName(String name) {
if (name2ctx.containsKey(name)) {
throw new IllegalArgumentException("Duplicate handler name: " + name);
}
}
private AbstractChannelHandlerContext getContextOrDie(String name) {
AbstractChannelHandlerContext ctx = (AbstractChannelHandlerContext) context(name);
if (ctx == null) {
throw new NoSuchElementException(name);
} else {
return ctx;
}
}
private AbstractChannelHandlerContext getContextOrDie(ChannelHandler handler) {
AbstractChannelHandlerContext ctx = (AbstractChannelHandlerContext) context(handler);
if (ctx == null) {
throw new NoSuchElementException(handler.getClass().getName());
} else {
return ctx;
}
}
private AbstractChannelHandlerContext getContextOrDie(Class<? extends ChannelHandler> handlerType) {
AbstractChannelHandlerContext ctx = (AbstractChannelHandlerContext) context(handlerType);
if (ctx == null) {
throw new NoSuchElementException(handlerType.getName());
} else {
return ctx;
}
}
// A special catch-all handler that handles both bytes and messages.
static final class TailContext extends AbstractChannelHandlerContext implements ChannelInboundHandler {
private static final String TAIL_NAME = generateName0(TailContext.class);
TailContext(DefaultChannelPipeline pipeline) {
super(pipeline, null, TAIL_NAME, true, false);
}
@Override
public ChannelHandler handler() {
return this;
}
@Override
public void channelRegistered(ChannelHandlerContext ctx) throws Exception { }
@Override
public void channelUnregistered(ChannelHandlerContext ctx) throws Exception { }
@Override
public void channelActive(ChannelHandlerContext ctx) throws Exception { }
@Override
public void channelInactive(ChannelHandlerContext ctx) throws Exception { }
@Override
public void channelWritabilityChanged(ChannelHandlerContext ctx) throws Exception { }
@Override
public void handlerAdded(ChannelHandlerContext ctx) throws Exception { }
@Override
public void handlerRemoved(ChannelHandlerContext ctx) throws Exception { }
@Override
public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception { }
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
logger.warn(
"An exceptionCaught() event was fired, and it reached at the tail of the pipeline. " +
"It usually means the last handler in the pipeline did not handle the exception.", cause);
}
@Override
public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
try {
logger.debug(
"Discarded inbound message {} that reached at the tail of the pipeline. " +
"Please check your pipeline configuration.", msg);
} finally {
ReferenceCountUtil.release(msg);
}
}
@Override
public void channelReadComplete(ChannelHandlerContext ctx) throws Exception { }
}
static final class HeadContext extends AbstractChannelHandlerContext implements ChannelOutboundHandler {
private static final String HEAD_NAME = generateName0(HeadContext.class);
final Unsafe unsafe;
HeadContext(DefaultChannelPipeline pipeline) {
super(pipeline, null, HEAD_NAME, false, true);
unsafe = pipeline.channel().unsafe();
}
@Override
public ChannelHandler handler() {
return this;
}
@Override
public void handlerAdded(ChannelHandlerContext ctx) throws Exception {
// NOOP
}
@Override
public void handlerRemoved(ChannelHandlerContext ctx) throws Exception {
// NOOP
}
@Override
public void bind(
ChannelHandlerContext ctx, SocketAddress localAddress, ChannelPromise promise)
throws Exception {
unsafe.bind(localAddress, promise);
}
@Override
public void connect(
ChannelHandlerContext ctx,
SocketAddress remoteAddress, SocketAddress localAddress,
ChannelPromise promise) throws Exception {
unsafe.connect(remoteAddress, localAddress, promise);
}
@Override
public void disconnect(ChannelHandlerContext ctx, ChannelPromise promise) throws Exception {
unsafe.disconnect(promise);
}
@Override
public void close(ChannelHandlerContext ctx, ChannelPromise promise) throws Exception {
unsafe.close(promise);
}
@Override
public void deregister(ChannelHandlerContext ctx, ChannelPromise promise) throws Exception {
unsafe.deregister(promise);
}
@Override
public void read(ChannelHandlerContext ctx) {
unsafe.beginRead();
}
@Override
public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) throws Exception {
unsafe.write(msg, promise);
}
@Override
public void flush(ChannelHandlerContext ctx) throws Exception {
unsafe.flush();
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
ctx.fireExceptionCaught(cause);
}
}
}